In an isotonic contraction, tension remains the same, whilst the muscle's length changes.
The effect is not visible during the classic biceps curl, which is in fact auxotonic because the resistance (torque due to the weight being lifted) does not remain the same through the exercise.
Tension is highest at a parallel to the floor level, and eases off above and below this point.
[citation needed] There are two main features to note regarding eccentric contractions.
For example, the heart's ventricles contract to expel blood into the pulmonary artery and aorta.